Compact disc players have existed for some years. Initially, the compact disc players utilized a single disc that could be mounted and removed from the unit as desired.
In more recent times, a relatively standard feature on audio equipment has been turntables to accommodate multiple compact discs so that the turntable may selectively rotate one of the discs into a playing position.
A common form of multiple compact disc turntable utilizes recesses to position the discs themselves on the turntable. When the desired disc is rotated into the play position, the drive and reading unit of the compact disc player engages the disc, lifts the disc from the turntable into position where it may be rotated and plays the disc.
The difficulty with such conventional apparatus is that the units must be maintained in a relatively stable horizontal position to avoid any dislodgement of the discs when in the out-of-play positions which may cause both damage to the disc as well as causing the disc to be improperly placed if rotated to the in-play position. The discs are generally supported laterally in the recess and supported underneath by the turntable itself. However, there is no retention of the disc within the recess other than that provided by gravity.
To add greater flexibility in the design of audio equipment, recent developments have included compact disc players which can be arranged in the vertical position. However, these arrangements have generally been restricted to players capable of retaining only a single compact disc. A typical example of such an apparatus securely fixes the disc onto the drive spindle so that, even in the vertical position, the disc is securely held. The securing of the discs in this position has involved such apparatus as retaining means on the spindle itself in the form of spring biased ball bearings protruding from the spindle. The compact disc is fitted over the spindle and pushed past the ball bearings which must recess into the spindle to allow the compact disc to be fitted in place. The spring bias then causes the ball bearings to protrude on the far side of the compact disc from the seat provided on the drive spindle.
Although such an arrangement is suitable for a single compact disc, it does not accommodate a multiple compact disc turntable which requires an easier fixing and release of the compact disc in the in-play position as well as the need to securely support the compact discs in the out-of-play positions.